ANCHEZ.ITGO.COM

Aquaria kept in homes by hobbyists can be as small as 3 U.S. gallons (11 L). This size is widely considered the smallest practical system with filtration and other basic systems; indeed, the local government of Rome, Italy, has recently taken the step of banning traditional goldfish bowls as inhumane. Practical limitations, most notably the weight (fresh water weighs about 8.3 pounds per U.S. gallon (1 kg/L), and salt water is even denser) and internal water pressure (requiring thick, strong glass siding) of a large aquarium, keep most home aquaria to a maximum of around 1 m? (300 U.S. gallons). However, some dedicated aquarists have been known to construct custom aquaria of up to several thousand U.S. gallons (several cubic meters), at great effort and expense.